ROCKVILLE, Md. (AP) — A man has been convicted of first-degree murder in the killing of his 12-year-old stepdaughter in the basement of their Maryland home last year.

Forty-three-year-old David R. Hang was convicted Wednesday by a Montgomery County Circuit Court jury in the death of Jessica Nguyen. Prosecutors say Hang stabbed Jessica more than 40 times on May 31, 2011, at their Gaithersburg townhouse.

Police say Hang entered into a sham marriage several years ago with Jessica's mother, a Vietnamese woman facing immigration problems. Prosecutors say Hang became angry over a drawn out divorce with Jessica's mother.

The defense argued that Hang was at a doctor's appointment in Virginia when Jessica was killed.

Hang is scheduled to be sentenced on Oct. 29. Prosecutors plan to ask for life without the possibility of parole.